REQUIRES 'VARIANTS' MODULE
The labels are configured in the admin client, see Label and Workflow Configuration. Labels can be grouped in the UI and/or have different functionality besides flagging items:
Labels in or groups allow you to select none, one or more labels from a group
XOR Label Groups are similar to or groups, but you can always only select of the labels.
Review groups are similar to XOR groups, but have some additional possibilities, e.g. when changing an item after a review the review status can be reset automatically.
Example Simple Review Flag
Design Review Labels
Design Review Labels allow you to define a small questionnaire which has to be filled when you want to set the label. It's also possible to require that the user enters a password to do so.
Example Simple Review Form